In these years, there are lots of location positioning apparatuses with the use of GPS. Examples are car navigation systems, mobile telephones, and the like. For instance, as to mobile telephones familiar to us, the services are provided to identify the user's current location and guide the user to a destination with a dedicated map application downloaded to operate on a GPS mobile telephone equipped with the GPS function.
As an example, regarding the GPS positioning function of the mobile telephone also provided overseas, assist data including trajectory information of satellites or current time information, general location information indicating the user's rough location, and the like, is generated on the communication network side. The assist data is notified to the mobile telephone via the communication network so that GPS satellite search process or the positioning arithmetic process are performed in consideration of the assist data on the mobile telephone side. Assisted Global Positioning System (AGPS) tends to be often employed in these years.
As to the accuracy of the general position of the assist data in this AGPS, the error range can be set to a radius area from 0 to 1800 km in the standard specification. This enables the identification of the location information ranging from a cell-level range extremely close to an actual current location to a nation-level range. In addition, the error range significantly differs depending on the communication operator, in each nation, for providing the GPS function. Furthermore, it is already known that when the accuracy of the above general location is low, the accuracy of the positioning result in AGPS is also low.
Accordingly, in the mobile telephone with the use of AGPS, even in a case where a relatively wide area of the general location is identified, about 90 seconds, for example, is set to a timeout period for ending, that is, timing out the positioning measurement in order to increase the positioning success rate, even if the positioning measurement result is not acquirable.
Patent Document 1, however, discloses a location positioning apparatus for determining firstly whether or not a user is located in a radio wave coverage, when the user carries out an operation for acquiring the location information, and for acquiring the location information of the terminal, only when the user is located in the radio wave coverage. This intends to eliminate the need of the operation for acquiring the location information again when the user moves into the radio wave coverage, once the user carries out the operation for acquiring the location information while staying at the outside of the radio wave coverage.